Targeted paired-end sequencing of nascent RNA from S. cerevisiae

Targeted paired-end sequencing of cDNA from unfragmented nascent RNA from exponentially growing S. cerevisiae cells was employed to obtain Pol II transcription elongation and splicing information from single transcripts. Nascent RNA was prepared from the yeast chromatin fraction (Carrillo Oesterreich, Preibisch, Neugebauer, Mol Cell 2010) or enriched from total RNA with polyadenylated RNA depletion. The nascent 3’ end was labeled with a 3’ DNA adaptor through ligation. A PCR with a forward primer in the first exon of select intron-containing genes amplifies nascent transcripts of specific genes and ensures sequencing adaptor attachment for paired-end sequencing. With this approach co-transcriptional splicing progression with distance from the intron end could be analyzed for 87 genes. Note that the unmapped and mapped data also include genes that did not pass the read coverage requirements in SMIT analysis. Nascent RNA profiles for mainly intron-containing genes were generated with paired-end sequencing with Illumina HiSeq technology.